The Katanas legendary strength and fatal efficiency are recognized the world over by way of fables, legends, folklore and verifiable truth. For the samurai warriors of ancient Japan the katana was the sword of choice. The narrow, curved sword along with its single cutting edge gave the Japanese katana its distinctive look and feel. A Japanese katanas blade is at least 60 cm long with an extended grip for holding with not one but two hands. The hand shield is traditionally circular or square. In literal terms in Japan the word katana is usually chosen to identify any sword with only one edgeIt doesn't necessarily even need to be of Japanese origin. However, in modern English usage the word katana refers specifically to the sword of the samurai. As battle conditions became more desperate during the Muromachi period (1392-1573) the demand for more effective weaponry gave rise to the katana. The katana made it possible for the samurai to pull out their sword and cut their adversaries in one swift movement which the new sword made possible because it is worn with the sharp edge facing up.
The true beauty of the katana is in its masterful construction. The Japanese had an understanding of metallurgy that was far more advanced than anything that Europeans were working on at the time. The Japanese developed a type of steel called Tamahagane that was used to make genuine samurai swords. A blend of high carbon and low carbon steel, each with their own unique properties, is used to create Tamahagane. High carbon steel is very hard and can be made exceptionally sharp, the trade-off being that it is likewise very brittle and will easily break if it's subjected to excessive levels of force. Steel with a low carbon content is softer which makes it better for absorbing impact but also makes the edge very easily blunted. Incorporating both types of steel in a single weapon was the real inspiration of the traditional samurai sword maker. Both kinds of steel were merged by using the high carbon steel to create the outside of the blade and its cutting edge and making use of low carbon steel to create a strength giving core.
The method of creating a single sword from two pieces of metal was accomplished by creating a U-shaped bar from high carbon steel and putting a length of low carbon steel into the U and hammering them together into a single piece of metal. The heating, folding and hammering phase of sword creation took anywhere from a few days to a week to finish depending on the sword maker. Repeatedly working the metal had a two-fold result, the first one being to force pollutants from the metal and the second one being to produce microscopic defects in the molecular lattice of the metal, adding strength. This is the distinction between forged and cast metal, forged metal has been hammered into shape and is much stronger than cast metal which has only been made molten and put into a form (cast) and permitted to harden. Typically the katana was folded a maximum of 16 times before being worked into the simple shape of a sword. At the end of the forging process the katana would have had little or no curve which was produced by an inspired system of quenching. A clay slurry, unique to each sword maker, was the key to the quenching process as it was utilized to insulate the blade in varying degrees. By putting a heavier coat on the spine and a thinner coating on the sharp edge a heat gradient could be produced. This pattern of insulation would cause the blades sharp edge to cool very quickly and harden during quenching process while the spine would cool more slowly and contract somewhat rather than immediately harden. The characteristic curve of the katanas blade is caused by the slight shrinking of the spine over the course of a number of quenching cycles.
With the price of a traditionally made katana potentially exceeding tens of thousands of dollars, they can be prohibitively expensive. However, katanas made from modern steel are available today at accessible prices and although they don't have the "soul" of a traditional katana most are faithful and high quality reproductions that can be purchased from companies that specialize in selling martial arts supplies.
About Author / Additional Info:
Ian Boen lives together with his partner and two children in Scottsdale, Az. He works for a martial arts supply company in Phoenix, AZ. Check us out at http://www.karatemart.com